+ # cat /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/hist
+
+ # event histogram
+ #
+ # trigger info: hist:keys=pid,prio,lat.log2:vals=hitcount:sort=lat.log2:size=2048 [active]
+ #
+
+ { pid: 2035, prio: 9, lat: ~ 2^2 } hitcount: 43
+ { pid: 2034, prio: 9, lat: ~ 2^2 } hitcount: 60
+ { pid: 2029, prio: 9, lat: ~ 2^2 } hitcount: 965
+ { pid: 2034, prio: 120, lat: ~ 2^2 } hitcount: 9
+ { pid: 2033, prio: 120, lat: ~ 2^2 } hitcount: 5
+ { pid: 2030, prio: 9, lat: ~ 2^2 } hitcount: 335
+ { pid: 2030, prio: 120, lat: ~ 2^2 } hitcount: 10
+ { pid: 2032, prio: 120, lat: ~ 2^2 } hitcount: 1
+ { pid: 2035, prio: 120, lat: ~ 2^2 } hitcount: 2
+ { pid: 2031, prio: 9, lat: ~ 2^2 } hitcount: 176
+ { pid: 2028, prio: 120, lat: ~ 2^2 } hitcount: 15
+ { pid: 2033, prio: 9, lat: ~ 2^2 } hitcount: 91
+ { pid: 2032, prio: 9, lat: ~ 2^2 } hitcount: 125
+ { pid: 2029, prio: 120, lat: ~ 2^2 } hitcount: 4
+ { pid: 2031, prio: 120, lat: ~ 2^2 } hitcount: 3
+ { pid: 2029, prio: 120, lat: ~ 2^3 } hitcount: 2
+ { pid: 2035, prio: 9, lat: ~ 2^3 } hitcount: 41
+ { pid: 2030, prio: 120, lat: ~ 2^3 } hitcount: 1
+ { pid: 2032, prio: 9, lat: ~ 2^3 } hitcount: 32
+ { pid: 2031, prio: 9, lat: ~ 2^3 } hitcount: 44
+ { pid: 2034, prio: 9, lat: ~ 2^3 } hitcount: 40
+ { pid: 2030, prio: 9, lat: ~ 2^3 } hitcount: 29
+ { pid: 2033, prio: 9, lat: ~ 2^3 } hitcount: 31
+ { pid: 2029, prio: 9, lat: ~ 2^3 } hitcount: 31
+ { pid: 2028, prio: 120, lat: ~ 2^3 } hitcount: 18
+ { pid: 2031, prio: 120, lat: ~ 2^3 } hitcount: 2
+ { pid: 2028, prio: 120, lat: ~ 2^4 } hitcount: 1
+ { pid: 2029, prio: 9, lat: ~ 2^4 } hitcount: 4
+ { pid: 2031, prio: 120, lat: ~ 2^7 } hitcount: 1
+ { pid: 2032, prio: 120, lat: ~ 2^7 } hitcount: 1
+
+ Totals:
+ Hits: 2122
+ Entries: 30
+ Dropped: 0
+
+
+The latency values can also be grouped linearly by a given size with
+the ".buckets" modifier and specify a size (in this case groups of 10).
+
+ # echo 'hist:keys=pid,prio,lat.buckets=10:sort=lat' >> \
+ /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
+
+ # event histogram
+ #
+ # trigger info: hist:keys=pid,prio,lat.buckets=10:vals=hitcount:sort=lat.buckets=10:size=2048 [active]
+ #
+
+ { pid: 2067, prio: 9, lat: ~ 0-9 } hitcount: 220
+ { pid: 2068, prio: 9, lat: ~ 0-9 } hitcount: 157
+ { pid: 2070, prio: 9, lat: ~ 0-9 } hitcount: 100
+ { pid: 2067, prio: 120, lat: ~ 0-9 } hitcount: 6
+ { pid: 2065, prio: 120, lat: ~ 0-9 } hitcount: 2
+ { pid: 2066, prio: 120, lat: ~ 0-9 } hitcount: 2
+ { pid: 2069, prio: 9, lat: ~ 0-9 } hitcount: 122
+ { pid: 2069, prio: 120, lat: ~ 0-9 } hitcount: 8
+ { pid: 2070, prio: 120, lat: ~ 0-9 } hitcount: 1
+ { pid: 2068, prio: 120, lat: ~ 0-9 } hitcount: 7
+ { pid: 2066, prio: 9, lat: ~ 0-9 } hitcount: 365
+ { pid: 2064, prio: 120, lat: ~ 0-9 } hitcount: 35
+ { pid: 2065, prio: 9, lat: ~ 0-9 } hitcount: 998
+ { pid: 2071, prio: 9, lat: ~ 0-9 } hitcount: 85
+ { pid: 2065, prio: 9, lat: ~ 10-19 } hitcount: 2
+ { pid: 2064, prio: 120, lat: ~ 10-19 } hitcount: 2
+
+ Totals:
+ Hits: 2112
+ Entries: 16
+ Dropped: 0
+